Details
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Bug
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Resolution: Unresolved
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P4: Low
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None
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5.15.2, 6.5.1.1
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None
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Linux/X11
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88075cc35 (dev), 3dfc872e3 (dev), 7fd802a64 (6.5), c27c7a78a (6.5)
Description
When storing list of strings, in an INI file, it's not always possible to get back the original value.
qsettings-string-list.py
from PySide6.QtCore import QSettings s = QSettings("test_py.ini", QSettings.IniFormat) s.setValue("empty_list", []) s.setValue("str", "foo") s.setValue("one", ["foo"]) s.setValue("empty_string", [""]) s.setValue("many", ["foo", "bar"]) s.setValue("many_empty_strings", ["", ""]) s.sync() shutil.copyfile("test_py.ini", "test_py_readonly.ini") s2 = QSettings("test_py_readonly.ini", QSettings.IniFormat) print("{:>18} {:>14} {:<14}".format("KEY", "FROM MEMORY", "FROM DISK")) for key in ( "missing", "empty_list", "str", "one", "empty_string", "many", "many_empty_strings", ): print("{:>18} {!r:>14} {!r:<14}".format(key, s.value(key), s2.value(key))) print("{:>18} {!r:>14} {!r:<14} type=list".format(key, s.value(key, type=list), s2.value(key, type=list))) print("{:>18} {!r:>14} {!r:<14} default=[]".format(key, s.value(key, []), s2.value(key, []))) print("{:>18} {!r:>14} {!r:<14} type=list default=[]".format(key, s.value(key, [], type=list), s2.value(key, [], type=list)))
$ python qsettings-string-list.py
KEY FROM MEMORY FROM DISK
missing None None
missing ['0'] ['0'] type=list
missing [] [] default=[]
missing [] [] type=list default=[]
empty_list [] None
empty_list [] [] type=list
empty_list [] None default=[]
empty_list [] [] type=list default=[]
str 'foo' 'foo'
str ['foo'] ['foo'] type=list
str 'foo' 'foo' default=[]
str ['foo'] ['foo'] type=list default=[]
one ['foo'] 'foo'
one [] ['foo'] type=list
one ['foo'] 'foo' default=[]
one [] ['foo'] type=list default=[]
empty_string [''] ''
empty_string [] [] type=list
empty_string [''] '' default=[]
empty_string [] [] type=list default=[]
many ['foo', 'bar'] ['foo', 'bar']
many [] [] type=list
many ['foo', 'bar'] ['foo', 'bar'] default=[]
many [] [] type=list default=[]
many_empty_strings ['', ''] ['', '']
many_empty_strings [] [] type=list
many_empty_strings ['', ''] ['', ''] default=[]
many_empty_strings [] [] type=list default=[]
test_py.ini
[General] empty_list=@Invalid() empty_string= many=foo, bar many_empty_strings=, one=foo str=foo
Observations:
- Reading the "missing" key with just `type=list` leads to a surprising results: `['0']`.
- Specifying `type=list` almost always returns an empty list (except for "str", the "missing"case above and "one" when read from disk).
- The generated file is the same as the C++ below, setValue(key, list) serialization looks ok.
- Reading an empty or single-element "FROM MEMORY" (the QVariant is cached internally?) vs "FROM DISK".
I tested the same in C++ and it work as I would expect:
qsettings-string-list.cpp
#include <QSettings> #include <QStringList> int main() { QSettings settings("test.ini", QSettings::IniFormat); settings.setValue("empty_list", QStringList()); settings.setValue("one", QStringList({ "foo" })); settings.setValue("empty_string", QStringList({ "" })); settings.setValue("many", QStringList({ "foo", "bar" })); settings.setValue("many_empty_strings", QStringList({ "", "" })); qDebug() << settings.value("missing").toStringList(); qDebug() << settings.value("empty_list").toStringList(); qDebug() << settings.value("empty_string").toStringList(); qDebug() << settings.value("one").toStringList(); qDebug() << settings.value("many").toStringList(); qDebug() << settings.value("many_empty_strings").toStringList(); return 0; }
$ ./qsettings-string-list
QList()
QList()
QList("")
QList("foo")
QList("foo", "bar")
QList("", "")
test.ini
[General] empty_list=@Invalid() empty_string= many=foo, bar many_empty_strings=, one=foo
There is a unit test for `type=list` in the repo but I suspect the test passes because it does not check the content of the returned value, just the type:
sources/pyside6/tests/QtCore/qsettings_test.ini
[General] var1=a, b, c var2=a
sources/pyside6/tests/QtCore/qsettings_test.py
class TestQSettings(unittest.TestCase): def testConversions(self): ... r = settings.value('var2', type=list) self.assertEqual(type(r), list)
Attachments
Issue Links
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- Closed
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Gerrit Reviews
| For Gerrit Dashboard: PYSIDE-2381 | ||||||
|---|---|---|---|---|---|---|
| # | Subject | Branch | Project | Status | CR | V |
| 489601,9 | Fix 3 strange cases in QSettings.value() round trips of a list | dev | pyside/pyside-setup | Status: MERGED | +2 | 0 |
| 489710,3 | Factor helper functions for QSettings.value() type coercion | dev | pyside/pyside-setup | Status: MERGED | +2 | 0 |
| 490031,2 | Factor helper functions for QSettings.value() type coercion | 6.5 | pyside/pyside-setup | Status: MERGED | +2 | 0 |
| 490037,2 | Fix 3 strange cases in QSettings.value() round trips of a list | 6.5 | pyside/pyside-setup | Status: MERGED | +2 | 0 |